bench_date.rb

  require 'benchmark'
  require 'benchmark/ips'
  require 'date'

  fi = Date.new(1926,6,1)
  Count = 5
  dates = Count.times.to_a.map { |i| fi + i }

  Benchmark.ips do |x|

    x.report "Date#mon " do |times|
      i = 0
      while i < times
        #(fi + i%2).mon
        j = 0
        while j < Count
          dates[j].mon
          j += 1
        end
        i += 1
      end
    end

    x.report "Date#mon2" do |times|
      i = 0
      while i < times
        (fi + i%2).mon
        i += 1
      end
    end

    x.report "Date#mon3" do |times|
      i = 0
      while i < times
        (fi + i).mon
        i += 1
      end
    end

    x.report "Date#mon4" do |times|
      i = 0
      while i < times
        fi.mon
        i += 1
      end
    end

    x.report "Date#new " do |times|
      i = 0
      while i < times
        Date.new(1926,6,1)
        i += 1
      end
    end
#
#    x.report "Date#year" do |times|
#      i = 0
#      while i < times
#        (fi + i%2).year
#        i += 1
#      end
#    end

    x.report "Date#+" do |times|
      i = 0
      while i < times
        newdate = fi + i
        i += 1
      end
    end

  end

gistfile1.txt

Charless-Mac-Pro:rubinius cremes$ bin/benchmark -trbx -t"jruby --server" -truby2 benchmark/core/date/bench_mon.rb 
=== bin/rbx ===
           Date#mon    564287.3 (±5.6%) i/s -    2811136 in   5.008319s (cycle=35584)
           Date#mon2    84906.7 (±3.1%) i/s -     427156 in   5.036177s (cycle=4643)
           Date#mon3    84892.3 (±1.8%) i/s -     430200 in   5.069337s (cycle=7170)
           Date#mon4  3748984.2 (±5.3%) i/s -   18699120 in   5.005900s (cycle=155826)
           Date#new    102422.3 (±6.2%) i/s -     519520 in   5.107136s (cycle=7640)
              Date#+   906731.6 (±2.0%) i/s -    4542048 in   5.011255s (cycle=47313)
=== jruby --server ===
           Date#mon    604013.6 (±6.0%) i/s -    3006234 in   5.001000s (cycle=30366)
           Date#mon2   679961.4 (±30.9%) i/s -    2163428 in   5.008999s (cycle=34894)
           Date#mon3   594166.0 (±39.6%) i/s -    1616972 in   5.405000s (cycle=37604)
           Date#mon4  4202300.5 (±7.4%) i/s -   20879463 in   5.009000s (cycle=88099)
           Date#new    760695.3 (±7.5%) i/s -    3783426 in   5.010000s (cycle=20341)
              Date#+   705049.0 (±47.5%) i/s -    1421850 in   5.048000s (cycle=56874)
=== ruby2 ===
           Date#mon   2180978.7 (±5.2%) i/s -   10894100 in   5.016489s (cycle=55300)
           Date#mon2  2030388.5 (±19.5%) i/s -    9749500 in   5.013922s (cycle=52700)
           Date#mon3  2202404.0 (±19.9%) i/s -   10567099 in   5.009852s (cycle=53101)
           Date#mon4 14567732.5 (±0.9%) i/s -   72806652 in   4.998209s (cycle=75604)
           Date#new   1670534.8 (±16.5%) i/s -    8113871 in   5.019878s (cycle=42481)
              Date#+  2980808.4 (±27.6%) i/s -   13749645 in   5.004015s (cycle=56121)

Comparing benchmark/core/date/bench_mon.rb:Date#new :
         ruby2:    1670534 i/s
jruby --server:     760695 i/s - 2.20x slower
       bin/rbx:     102422 i/s - 16.31x slower
Comparing benchmark/core/date/bench_mon.rb:Date#+:
         ruby2:    2980808 i/s
       bin/rbx:     906731 i/s - 3.29x slower
jruby --server:     705048 i/s - 4.23x slower
Comparing benchmark/core/date/bench_mon.rb:Date#mon4:
         ruby2:   14567732 i/s
jruby --server:    4202300 i/s - 3.47x slower
       bin/rbx:    3748984 i/s - 3.89x slower
Comparing benchmark/core/date/bench_mon.rb:Date#mon3:
         ruby2:    2202404 i/s
jruby --server:     594165 i/s - 3.71x slower
       bin/rbx:      84892 i/s - 25.94x slower
Comparing benchmark/core/date/bench_mon.rb:Date#mon2:
         ruby2:    2030388 i/s
jruby --server:     679961 i/s - 2.99x slower
       bin/rbx:      84906 i/s - 23.91x slower
Comparing benchmark/core/date/bench_mon.rb:Date#mon :
         ruby2:    2180978 i/s
jruby --server:     604013 i/s - 3.61x slower
       bin/rbx:     564287 i/s - 3.87x slower